The present invention generally relates to an electrophotographic copying machine and, more particularly, to a dual-mode copying machine wherein a copy can be made either in a primary scan mode in which an optical system is moved so as to scan a document to be copied placed on a stationary document support, or in a secondary scan mode in which the optical system is held stationary and a document to be copied is moved relative to the optical system.
Various types of electrophotographic copying machines are currently commercially available. Some of them are operable under a secondary scan mode, that is, are of the type having a movable document support and an immovable optical system, and the others are operable under a primary scan mode, that is, of a type having a stationary document support and a movable optical system. In other words, the conventional electrophotographic copying machines are available in either one of these two types.
Therefore, it often happens that relatively complicated and time-consuming procedures are required when a document that requires, for example, urgent copying is to be copied while different documents are being copied. More specifically, assuming that the copying machine is occupied by an office clerk who is making a number of copies from a single document, and in the even that another office clerk wishes to make a copy of an urgent document to be immediately copied, the first place document on the document support must be manually removed therefrom in favor of the urgent document and, at the same time, copy data associated with the urgent document must be entered in the machine. This is true even with the copying machine having an interrupted copying function. Moreover, after the completion of copy-making of the urgent document, the junior clerk's document (that is, the urgent document) must be removed from the document support and the senior clerk's document must be subsequently placed again on the document support for the continued copy-making of the senior clerk's document.
In this way, with the conventional copying machine of either type, the interruppted copying operation results in a complicated and time-consuming intervention.